Hi-rail vehicle

ABSTRACT

The invention to a hi-rail vehicle for normal travel along a highway and selective travel along railway tracks provided with a first paid of railway track engageable wheels moveable between a normal position out of engagement with a railway track and a position of railway track contact immediately in front of the front steering wheels of the vehicle for guiding the vehicle; and second pair of railway track engageable wheels movable between a normal position between the forward and rear drive wheels with a railway tracks and a position of guiding contact therewith.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional patentapplication Ser. No. 60/529,554, filed Dec. 15, 2003.

FIELD OF THE INVENTION

The present invention relates to vehicle construction and moreparticularly to a vehicle capable to traveling on railroad track orhighway.

BACKGROUND OF THE INVENTION

Part of the ongoing cost and responsibility of the continuing operationsof any rail system is the maintenance of the infrastructure. There aretwo approaches to the provision of ongoing maintenance: developing anin-house maintenance organization or contracting those services out tofirms specializing in such work. In a railroad environment there areneeds for both routine transportation of the staff overseeing the dailyoperations and for the work equipment to perform the corrective andpreventative maintenance functions.

The railroads of today, as with any infrastructure-based industry, havedeveloped a unique set of highly specialized equipment for theperformance of maintenance functions. The procurement of suchspecialized equipment not only requires a substantial initial capitalinvestment, but also is paired with the need to provide thoseindividuals trained to operate, repair and maintain that equipment.

In a railroad environment there is the need for transportation andmaintenance equipment that is not found in other transportation fieldssuch as the highway, marine, or air travel industries. Special vehiclesare required to provide rail-borne access to locations along theright-of-way that may not be accessible to standard highway vehicles.

For both inspection of the right-of-way and for general rail-borneaccess, it is common practice to equip normal highway vehicles with“hi-rail” gear. This equipment is mounted to the frame of the vehiclefront and back and consists of a set of steel wheels found on railroadrolling stock. This hi-rail gear is retractable and enables the vehicleto operate either on roads or on the rails of the track via the steelwheels. To operate on a railroad track a hi-rail equipped highwayvehicle is typically positions longitudinally over the track at a gradecrossing or other area where the roadway surface is approximately levelwith the top of the rails. The hi-rail gear is lowered into position,which raises the vehicle's front steering wheels off of the crossingsurface and raises the rear wheels slightly to allow the weight of thevehicle to bear on the steel wheels of the hi-rail gear. The vehicle isthen ready to proceed. The hi-rail gear allows the steel wheels to ridealong the rails, and the rear rubber tires, which are still in enoughcontact with the rail to provide traction and propel the vehicle. In thesame manner heavy construction vehicles ranging from cranes to dumptrucks can also be fitted with hi-rail gear to provide access to therailroad right-of-way by means of the rails.

Besides the hi-rail equipment there are also numerous pieces ofmaintenance equipment manufactured specifically for work on therailroads. These range from ballast tampers that are used to consolidateand stabilize the track bed, to equipment used to handle crossties.These are all highly specialized, often single-function pieces ofequipment, and their maintenance and procurement represent a significantportion of every railroad's capital expenditures.

There is an acknowledged need to be able to provide hi-rail access toportions of the proposed right-of-way that may not be accessible tohighway vehicles. It is assumed that there would be a fleet of vehiclesprovided for the personnel assigned to the management of a rail system.The number and type of vehicles to be provided and the means of doing so(purchase or lease) would be determined once staffing issues areresolved.

The installation of hi-rail equipment represents a relatively smallcapital investment and will provide unrestricted access to all areas ofthe right-of-way. It should be noted that the operators of thosevehicles would need to be specially trained on the railroad operatingrules and the proper operation of on-track equipment. The remainder ofthe fleet vehicles should be strictly highway vehicles to servemiscellaneous transportation needs as necessary.

Amongst the objectives in the design of hi-rail equipment is theinherent characteristic of the ability to readily traverse rail trackshaving ever decreasing radii. As the tracks are caused to assume smallerradii, the conventional hi-rail equipment tends to cause the leadingand/or trailing ends of the associated chassis to extend an unreasonabledegree beyond the track bed. Such conditions expose the overhangingportions of the hi-rail equipment to unwanted collision or impact withequipment on adjacent tracks and other stationery objects, which arenormally out of the zone of contact.

Accordingly, it is an objective of the present invention to produce ahi-rail equipment vehicle wherein the track engaging wheels are disposedto reduce the amount of overhang of the chassis permitting the equipmentto traverse track configuration of ever-decreasing radius.

SUMMARY OF THE INVENTION

The above, as well as other objectives of the invention, havesurprisingly been achieved by a hi-rail vehicle including a vehiclechassis; ground engaging wheels attached to the underside of the chassisincluding at least a pair of ground engageable steerable front wheelsand a bogie unit of front and rear driving wheels; at least a first pairof rail engaging wheels mounted for selective vertical movement in frontof the pair of ground engaging steerable front wheels; and at least asecond pair of rail engageable wheels mounted for selective verticalmovement interdigitated between the front and rear driving wheels of thebogie unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The above, as well as other objects and advantages of the invention,will become readily apparent to those skilled in the art from readingthe following detailed description of the invention when considered inthe light of the accompanying drawings, in which:

FIG. 1 is a side elevational view of a hi-rail equipment vehicleproduced in accordance with the present invention; and

FIG. 2 is a diagrammatic top plan view illustrating the disposition ofthe rail engaging wheels in respect of the hi-rail equipment vehiclechassis and an associated curved section of railway track.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

Referring to the drawings, there is illustrated a hi-rail equipmentvehicle generally designated by reference numeral 10 having a chassis12. The chassis 12 is fitted with couplers 14 and 16 on the front endand the rear end of the chassis 12, respectively.

The vehicle 10 includes an operators cab 18 and an associated driveengine within a normally closed hood 20. The chassis 12 is provided withsuitable structural details for supporting any desired equipment havinga centrally disposed crane 22. However, it will be understood the craneassembly can be substituted by many other types of railway maintenanceequipment, for example.

The vehicle chassis 12 is provided with sets of rail track engaging andguiding wheels and highway engaging wheels positioned in spaced relationalong the length thereof. More particularly, the chassis 12 of thevehicle 10 is adapted to travel along a highway on a pair of steerablefront wheels 24. The wheel assembly and associated steering mechanismare conventional and are typically mounted to the chassis 12 by means ofa conventional spring suspension mechanism. In the highway mode, thevehicle 10 is further provided with a bogie or tandem unit 26 consistingof spaced apart forward and rear sets of drive wheels 28 and 30,respectively. The bogie 26 is mounted to the chassis 12 by a suspensionassembly. The sets of drive wheels 28 and 30 are connected to a driveshaft through a standard differential drive gear assembly, not shown.The other end of the drive shaft typically extends to a conventionaltransmission used to transmit power from the drive engine to the sets ofdrive wheels 28 and 30.

In the rail mode, there is provided railway track front engageablewheels 32 mounted, for selective vertical movement to the chassis 12. Itwill be noted that the wheels 32 are mounted in front of the frontsteering wheels 24 and are mounted to the chassis 12 through independenttorsion spring suspension mechanism. The torsion spring mechanism isadapted to be selectively moved vertically. Normally, the wheels 32 arecarried in an elevated position, as illustrated in FIG. 1. When it isdesired to guide the front of the chassis 12 along a railway track, thetorsion spring mechanism is energized to force the wheels 32 downwardlyinto engagement with the railway track 46. Sufficient downward force isapplied to move the wheels 32 downwardly into engagement with therailway tracks, and simultaneously cause the steering wheels 24 to beurged upwardly. The procedure continues until the wheels 24 are out ofcontact with the supporting surface. At this point in the operation, therailway track engaging wheels 32 carry the load previously carried bythe steering wheels 24, and are thereby in position to guide the frontof the vehicle 10 along the railway tracks 46.

Interdigitated between the rear drive wheels 28 and 30 is disposed arear railway engageable wheel set 34 mounted to the chassis 12 forselective vertical movement. The wheel set 34 typically includes anassociated axle 36 which is mounted to extend between a forwardlyextending set of spaced apart arms 38. The rearward ends of the arms 38are affixed to a shaft 40 which, in turn, is pivotally disposed within ahollow mounting member 42 secured to the vehicle chassis 12.

The loading of the front railway engaging wheels 32 is typically carriedby suspension means such as torsion springs for example. The suspensionsprings are employed control the vertical movement of the wheels 32 toeffect a suitable loading of the rail engaging wheels 32 to effect asuitable loading of the rail engaging wheels and a simultaneousunloading of the steerable wheels 24 carrying a pneumatic tires forhighway use, as explained in some detail above.

The loading of the rear railway engageable wheel set 34 is typicallycarried out by a hydraulic system 44 which effectively connects therailway engageable wheels 34 and the associated axle 36 to the chassis12.

The rear railway engageable wheels 34 are positioned between the drivewheels 28 and 30 of the rear tandem to facilitate the travel of theassociated vehicle 10 on very tight curves of the railway track 46, asillustrated in FIG. 2.

It will be understood that during railway track travel, the railwayengaging wheels 34 are caused to be lowered from the normal position, asillustrated in FIG. 1, to a position contacting the railway track 46.Sufficient unloading of the drive wheels 28 and 30 is accomplished topermit enough tractive effort to occur between the drive wheels 28 and30 and the railway tracks 46, and simultaneously allow the railwayengaging wheels 34 to guide the rear of vehicle 10. The hydraulic system44 is deemed to be particularly beneficial to the overall operation ofthe hi-rail vehicle 10 due to the inherent ability to apply a constantforce between the wheels 34 and the supporting railway track 46 nomatter the irregularities the drive wheel 28 and 30 may encounter.Amongst the types of irregularities which may be encountered are “frogs”in the region of track switching mechanism. Such irregularities couldcause the railway engaging wheels 28 and 30 to encounter a raisedsurface of some two inches above normal track height. In such instances,the hydraulic system 44 will instantly compensate, by rapidly causingthe wheels 34 to maintain constant contact with the railway 46.

Thereby, the vehicle 10 is able to work in transit rail yards. Where therailway tracks are oftentimes formed on very short radii. Currently,hi-rail equipment is provided with front rail engaging wheels locatedbehind the front road wheels in an attempt to reduce the on-rail wheelbase. However, such arrangement results in a structure wherein the frontoverhang of the chassis is excessive and can interfere with adjoiningtrack vehicles and other obstructions. The arrangement of the presentinvention effectively reduces on-track vehicle overhang.

In accordance with the provisions of the patent statutes, the presentinvention has been described in what is considered to represent itspreferred embodiment. However, it should be understood that theinvention can be practiced otherwise than as specifically illustratedand described without departing from its spirit or scope.

1. A hi-rail vehicle including: a vehicle chassis; and ground engagingwheels attached to the underside of the chassis including at least apair of ground engageable steerable front wheels and a bogie unit offront and rear driving wheels; at least a first paid of rail engagingwheels mounted for selective vertical movement in front of the pair ofground engaging steerable front wheels; and at least a second pair ofrail engageable wheels mounted for selective vertical movementinterdigitated between the front and rear driving wheels of the bogieunit.
 2. A hi-rail vehicle for normal travel along a highway andselective travel along railway tracks comprising: a vehicle chassis; apair of highway engageable front steering wheels connected to saidchassis; at least a first pair of railway track engageable wheelsmounted to said chassis in front of said pair of highway engageablesteering front wheels; means for selectively imparting vertical movementto said first paid of railway track engageable wheels to cause selectivehighway engagement of said pair of steering front wheels; a tandem unitof spaced apart forward and rear highway engageable wheel sets connectedto said chassis; at least a second pair of railway track engageablewheels mounted for vertical movement between the forward and rearhighway engageable wheel sets of said tandem unit; and means forselectively imparting vertical movement to said second pair of railengageable wheels to at least partially unload the wheel sets of saidtandem unit to provide motive traction between the vehicle andassociated railway tracks and simultaneously cause said second pair ofrailway track engageable wheels to assist in guiding the vehicle alongthe associated railway tracks.
 3. A hi-rail vehicle as defined in claim2 wherein said vehicle chassis includes a front end and spaced apartrear end.
 4. A hi-rail vehicle as defined in claim 3 wherein said pairof ground engageable front steering wheels are connected to the frontend of said vehicle chassis.
 5. A hi-rail vehicle as defined in claim 4wherein said tandem unit is connected to the rear end of said vehiclechassis.
 6. A hi-rail vehicle as defined in claim 5 wherein said pair ofground engageable front steering wheels and said tandem unit are mountedto said chassis in spaced apart relation to one another.
 7. A hi-railvehicle as defined in claim 2 wherein said means for selectivelyimparting vertical movement to said second pair of railway trackengageable wheels includes an axle for supporting the railway trackengageable wheels.
 8. A hi-rail vehicle as defined in claim 7 whereinsaid means for selectively imparting vertical movement to said secondpair of rail engageable wheels further includes a pair of arms, each ofsaid arms having a maximal end and a spaced apart distal end.
 9. Ahi-rail vehicle as defined in claim 8 wherein the proximal ends of saidpair of arms are pivotally connected to said chassis.
 10. A hi-railvehicle as defined in claim 9 wherein the distal ends of said pair ofarms are connected to the axle of said means for imparting verticalmovement to said second pair of railway track engageable wheels.
 11. Ahi-rail vehicle as defined in claim 9 including a shaft pivotallymounted to said chassis wherein the proximal ends of said pair of armsare connected to said shaft.
 12. A hi-rail vehicle as defined in claim11 wherein said shaft is pivotally supported by a hollow mounting memberconnected to said chassis.
 13. A hi-rail vehicle as defined in claim 2wherein said means for imparting vertical movement to said second pairof railway track engageable wheels includes an air bag suspensionspring.
 14. A hi-rail vehicle as defined in claim 2 wherein said meansfor selectively imparting vertical movement to said first paid ofrailway track engageable wheels includes an air bag suspension spring.